This invention relates to a method of covering the bottom surface in a gas cavern suitable for storing natural gas or other gaseous fuels. Generally the conditions of temperature and pressure in such caverns are in the range of from 50.degree. to 70.degree. C and from about 20 to 120 atmospheres. Under these conditions, the water in the bottom of the cavern evaporates and mixes with the natural gas or gaseous fuel stored therein. During storage, the natural gas, which is initially in dry form, becomes saturated with water vapor, generally in approximately 5 to 7 months after the natural gas has been introduced into the cavern. Therefore, upon reclaiming or reproducing the gas for reuse it must be passed through a drier in order to separate the water vapor from the gas as completely as possible. This separation is time consuming and costly. Furthermore, the methods may require introducing supplemental methanol in order to avoid the formation of hydrates in the cavern riser tubes that provide means for supply and withdrawal of the storage gas.
It is thus the object of the present invention to provide a method for minimizing or preventing the water in the bottom of a cavern used for storing gaseous hydrocarbons to become mixed with the stored gaseous hydrocarbons, thereby making it possible to recover the stored gaseous hydrocarbon more quickly and economically.